"We will therefore have to think creatively about how we ensure that the law is capable of equal application, and is applied equally and fairly, against the mainstream media and bloggers, tweeters and other amateur online journalists," he said.

He warned that if changes were not made, there was a risk the established media would be tempted to cut corners or bend the law as it went up against amateur online journalists.

"It may encourage unethical and, potentially, unlawful practices to get a story," he said.

"The effect then is an indirect one, and one which lies behind the headline and the front-page scoop.

"In a culture which sees some act with impunity in the face of the civil law, and the criminal law, a general decline in standards may arise."

Lord Justice Leveson would not elaborate on his 17-month inquiry, which controversially recommended greater regulation of the British press.

He was also hesitant to comment about the 2Day FM royal phone prank.

A London nurse committed suicide last week after answering the hoax call from the Sydney radio station enquiring about the health of the pregnant Duchess of Cambridge.

Lord Justice Leveson says there are lessons that can be learned from the tragedy.

"I am absolutely sure there are a large number of lessons to be learned," he said after the speech.

"But you will forgive me, if as I understand it the police in London are in investigating this and I still remain a judge in England and Wales and might be called upon to decide something in the future.

"So I'm sure there are lessons to be learned but I'm not going to discuss them."